function handleComboChange(dropBoxID, textBoxID) {
    var dropBox = document.getElementById(dropBoxID);
    var textBox = document.getElementById(textBoxID);
    if (dropBox && textBox) {
        var dropBoxValue = dropBox.options[dropBox.selectedIndex].value;
        if (dropBoxValue == '0') {
            textBox.style.visibility = 'visible';
            textBox.focus();
        }
        else {
            textBox.style.visibility = 'hidden';
            textBox.value = '';
        }
    }
}